LegendCellPadding.fromLTRBPx constructor
      const
      LegendCellPadding.fromLTRBPx()
     
    
Creates padding in pixels from the left, top, right, and bottom.
Implementation
const LegendCellPadding.fromLTRBPx(
    this.leftPx, this.topPx, this.rightPx, this.bottomPx)
    : leftPct = null,
      topPct = null,
      rightPct = null,
      bottomPct = null;